fix: kop.bind.ip ignored when using label prefix (resolves #82)

Author: chetan

docker_helpers_test.go

@@ -397,7 +397,8 @@ func assertServiceIPs(t *testing.T, store TraefikStore, svcs []svc) {
 		assert.Equal(t,
 			svc.ip,
 			val,
-			"service has wrong IP at key: %s",
+			"service %s has wrong IP at key: %s",
+			svc,
 			key,
 		)
 	}

docker_proxy.go

@@ -160,6 +160,7 @@ func (s *DockerProxyServer) start() (*fiber.App, string) {
 		app.Use(logger.New())
 	}
 
+	app.All("/_ping", func(ctx *fiber.Ctx) error { return ctx.SendStatus(fiber.StatusNoContent) })
 	app.Get("/v*/version", s.handleVersion)
 	app.Get("/v*/containers/json", s.handleContainersList)
 	app.Get("/v*/containers/:id/json", s.handleContainerInspect)

docker_proxy_test.go

@@ -63,3 +63,34 @@ func Test_dockerProxyServerPrefix(t *testing.T) {
 	assert.Empty(t, g(store, fmt.Sprintf("traefik/http/routers/%s/service", "hello-detect2")))
 	assert.NotEmpty(t, g(store, fmt.Sprintf("traefik/http/routers/%s/service", "prefixed")))
 }
+
+// test that services with kop.bind.ip or foo.kop.bind.ip labels are handled correctly
+func Test_dockerProxyServerPrefixWithKopBindIP(t *testing.T) {
+	mockDockerEndpoint := dockerEndpoint
+	mockDockerClient := dc
+
+	// now create our proxy pointing to the mock
+	proxyServer := createProxy(mockDockerClient, "foo")
+	_, proxyDockerEndpoint := proxyServer.start()
+
+	var err error
+	dockerEndpoint = proxyDockerEndpoint
+	dc, err = createDockerClient(proxyDockerEndpoint)
+	assert.NoError(t, err, "should create docker client")
+	defer func() {
+		dockerEndpoint = mockDockerEndpoint
+		dc = mockDockerClient
+	}()
+
+	// both services get mapped to the same port (error case)
+	store := processFile(t, "hellodetect.yml")
+	processFileWithConfig(t, store, nil, "prefix-bindip.yml")
+
+	assertServiceIPs(t, store, []svc{
+		{"prefixed", "http", "http://foo.bar.baz:5588"},
+		{"unprefixed", "http", "http://example.local:5599"},
+	})
+
+	assert.Empty(t, g(store, fmt.Sprintf("traefik/http/routers/%s/service", "hello-detect2")))
+	assert.NotEmpty(t, g(store, fmt.Sprintf("traefik/http/routers/%s/service", "prefixed")))
+}

docker_test.go

@@ -17,6 +17,7 @@ var dc client.APIClient
 var dockerAPI = &DockerAPIStub{}
 
 func setup() {
+	os.Unsetenv("DOCKER_HOST") // make sure this doesn't interfere with our client setup
 	app, dockerEndpoint = createHTTPServer()
 	var err error
 	dc, err = createDockerClient(dockerEndpoint)

fixtures/prefix-bindip.yml

@@ -0,0 +1,28 @@
+services:
+  # test labels with a prefix, i.e., DOCKER_PREFIX=foo.
+  dockerprefix:
+    image: nginx
+    restart: "no"
+    ports:
+      - 5588:80
+    labels:
+      - "foo.traefik.enable=true"
+      - "foo.traefik.http.routers.prefixed.rule=Host(`hello-prefix.local`)"
+      - "foo.traefik.http.routers.prefixed.service=prefixed"
+      - "foo.traefik.http.routers.prefixed.tls=true"
+      - "foo.traefik.http.routers.prefixed.tls.certresolver=default"
+      - "foo.traefik.http.services.prefixed.loadbalancer.server.scheme=http"
+      - "foo.kop.bind.ip=foo.bar.baz"
+  dockerprefix2:
+    image: nginx
+    restart: "no"
+    ports:
+      - 5599:80
+    labels:
+      - "foo.traefik.enable=true"
+      - "foo.traefik.http.routers.unprefixed.rule=Host(`hello-prefix2.local`)"
+      - "foo.traefik.http.routers.unprefixed.service=prefixed"
+      - "foo.traefik.http.routers.unprefixed.tls=true"
+      - "foo.traefik.http.routers.unprefixed.tls.certresolver=default"
+      - "foo.traefik.http.services.unprefixed.loadbalancer.server.scheme=http"
+      - "kop.bind.ip=example.local"

traefik_kop.go

@@ -93,9 +93,21 @@ func Start(config Config) {
 
 	if config.DockerPrefix != "" {
 		// use proxy to filter by label prefix
+		//
+		// Docker client is used in two places:
+		// 		- Docker Provider which is used by traefik
+		//    - dockerCache used by traefik-kop to lookup container info
+		//
+		// The real docker client is only used by the proxy.
+		// All other usage goes via docker client connecting to the proxy.
+
 		dockerProxy := createProxy(dockerClient, config.DockerPrefix)
 		_, dockerProxyAddr := dockerProxy.start()
 		config.DockerHost = dockerProxyAddr
+		dockerClient, err = createDockerClient(dockerProxyAddr)
+		if err != nil {
+			log.Fatal().Msgf("failed to create docker client for proxy: %s", err)
+		}
 	}
 
 	dp := newDockerProvider(config)